Sputtering apparatus and method of preventing damage thereof

ABSTRACT

A sputtering apparatus includes a container; a plate for supporting the container; a first attachment for attaching the container to the plate; and a second attachment for less tightly attaching the container to the plate than through the first attachment.

This application claims the benefit of Korean Patent Application No.P2005-055521 filed in Korea on Jun. 27, 2005, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sputtering apparatus, and moreparticularly, to a sputtering apparatus configured to prevent damage toa container.

2. Description of the Related Art

When substrates for semiconductor wafers or liquid crystal panels aremanufactured, they are subjected to various repeating treatmentprocesses, such as thin film processing and etching. A sputteringapparatus is generally used for such thin film processing. A sputteringapparatus is an apparatus for forming thin film, for example, and is anindispensable component in the manufacturing of semiconductor devicesand liquid crystal display devices (LCDs). In light of the complicatedprocesses required for manufacturing large panels, and a need toincrease manufacturing yields, robotic technology is being increasinglyused for automating the operation of sputtering apparatuses.

FIG. 1 is a schematic view of a related art cluster-type sputteringapparatus. Referring to FIG. 1, a related art cluster-type sputteringapparatus includes a substrate retaining portion 108 for retaining asubstrate 107 over a specified duration, and a sputtering portion 109for sputtering the substrate 107 retained by the substrate retainingportion 108. The substrate retaining portion 108 includes a substrateretaining plate 110 that moves horizontally or vertically by means of ashaft 111.

A container 118 is provided at the front of the substrate retainingplate 110. The container 118 can be formed of quartz or pyrex, forexample. Quartz and pyrex have to be handled carefully because theycontain a large amount of glass, and are susceptible to damage fromoutside pressures.

A sheath heater 119 is provided at the rear of the substrate forcontrolling temperature. The sheath heater 119 may be installed withinthe substrate retaining plate 110.

The substrate 107 to be treated is placed on the container 118. In thiscase, heat generated by the sheath heater 119 can be transmitted to thesubstrate 107 through the container 118. The temperature of thecontainer 118 must be uniformly maintained to form a uniform film on thesubstrate 107. Thus, the container 118 is made of an appropriatelyselected material.

A vacuum pump 117 is provided for discharging air and creating a vacuumin the sputtering apparatus. A discharge nozzle (not shown) is providedat the bottom of the substrate retaining plate 110 for discharging agas, for example Ar gas.

The sputtering portion 109 includes a cathode 114 for supplying anegative voltage, a target 115 provided at the front of the cathode 114for discharging a target material through collision created by positiveions of a gaseous plasma, and a magnet 116 provided at the rear of thecathode 114 for forming a magnetic field around the target 115 togenerate more positive ions. A shield magnet 112 is provided along aninner surface of a main body 113 to separate the substrate retainingportion 108 from the sputtering portion 109.

During sputtering operation, the substrate 107 is positioned on thecontainer 118. Then, the shaft 111 moves the substrate retaining plate110 vertically, so that the substrate 107 faces the target 115. Next, Argas, for example, is discharged from the discharge nozzle. Then, plasmais generated by applying a high voltage. Here, ionic Ar+ ions collidewith the target 115, and particles separated from the target 115 aredeposited on the substrate 107.

As described above, the substrate 107 is positioned on the container118. The container 118 usually has a diameter larger than that of thesubstrate 107. Thus, when the substrate 107 is positioned on thecontainer 118, the container 118 is not covered entirely by thesubstrate 107. Thus, during plasma generation, particles from the target115 adhere to uncovered portions of the surface of the container 118.After continued plasma generation, these particles from the target 115peel off from the uncovered portions of the surface of the container118. The target material that peels off becomes an impurity that adheresto and contaminates the substrate 107.

Moreover, the uncovered portions of the surface of the container 118 iseasily damaged by the high-temperature plasma.

Therefore, in various sputtering apparatuses, the container 118 isreplaced by a new container 118, or the container 118 is removed,thoroughly washed to discard the target material adhered onto thesurface of the container 118, and then re-installed in the sputteringapparatus. When transporting the container 118 to be washed, carelesshandling can lead to damage of the container.

FIG. 2 is a plan view of the related art container of FIG. 1. Referringto FIG. 2, fixing holes 118 a and 118 b are provided on opposite sidesof the container 118. The container 118 is fixed to the substrate 107retaining plate 110 through these fixing holes 118 a and 118 b.

The container 118 expands due to the heat generated by the hightemperature plasma. The opposite sides of the container 118 are fixed tothe substrate retaining plate 110, so that there is no freedom ofmovement for the container 118. As such, the container 118 is easilydamaged from heat expansion.

As discussed above, the related art cluster-type sputtering apparatusmay cause contamination of the substrate due to the adherence andsubsequent peeling off of target material on exposed portions of thecontainer. Moreover, the related art container can be easily damaged dueto expansion caused by the high temperature plasma.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a sputtering apparatusthat substantially obviates one or more problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide a sputtering apparatusthat is damage resistant.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, asputtering apparatus includes a container; a plate for supporting thecontainer; a first attachment for attaching the container to the plate;and a second attachment for less tightly attaching the container to theplate through the first attachment.

In another aspect, a sputtering apparatus includes a plate; and acontainer having a first container fixing hole and a second containerfixing hole formed on opposite sides of the container, wherein thecontainer is attached through the first container fixing hole to theplate, and less tightly attached through the second container fixinghole to the plate than through the first container fixing hole.

In another aspect, a method for preventing damage to a sputteringapparatus includes attaching a container to a plate through a firstcontainer fixing hole provided at one side of the container; and lesstightly attaching the container to the plate through a second containerfixing hole provided at an opposite side of the container than throughthe first container fixing hole.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a schematic view of a related art cluster-type sputteringapparatus;

FIG. 2 is a plan view of the related art container of FIG. 1;

FIG. 3 is a plan view of an exemplary container according to anembodiment of the present invention;

FIG. 4A is a cross-sectional view of an exemplary fixing hole along lineA-A′ of FIG. 3; and

FIG. 4B is a cross-sectional view of an exemplary fixing hole along lineB-B′ of FIG. 3.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

FIG. 3 is a plan view of an exemplary container according to anembodiment of the present invention. Referring to FIG. 3, a container 20is fixed and connected to a plate (not shown). The plate is provided ona clustering-type sputtering apparatus. A shaft connected to the plateprovides vertical and horizontal motion for the plate.

A heater (not shown) can be provided for generating heat. In anembodiment, the heater can be provided inside the plate. In an anotherembodiment, the heater can be provided below the plate. The container 20is maintained at a uniform temperature by transferring heat from theheater to the container 20. In this case, for thin film processing, thecontainer 20 can maintain a uniform temperature by receiving heatthrough a substrate seated on the container 20 or contact with thecontainer 20. Thus, by processing the thin film through the plasmaprocess while the substrate is maintained at a uniform temperature, aneven thin film can be formed on the substrate.

Container fixing holes 22 and 24 are formed on either side of thecontainer 20 for attaching the container 20 to the plate. The diametersof the container fixing holes 22 and 24 on either side can be different.For example, the container fixing hole 24 at a first side of thecontainer 20 may have a diameter that is larger than the containerfixing hole 22 at a second side of the container 20. One reason forproviding different diameters for the container fixing holes 22 and 24is to loosely attach one of the sides of the container 20 to the platethrough the larger container fixing hole 24. Thus, the container 20 canbe attached more tightly through the container fixing hole 22 thanthrough the container fixing hole 24. Alternatively, the container 20can be attached less tightly through the container fixing hole 24 thanthrough the container fixing hole 22.

FIG. 4A is a cross-sectional view of an exemplary fixing hole along lineA-A′ of FIG. 3. Referring to FIG. 4A, the container 20 is tightlyattached to a plate 10 through the container fixing hole 22 on the firstside of the container 20. For this purpose, a plate fixing hole 32 isprovided through the plate 10 to correspond to container fixing hole 22on the first side of the container 20. In an embodiment, the containerfixing hole 22 on the first side of the container 20 and thecorresponding plate fixing hole 32 may be both threaded for screws.Thus, a screw 26 can be used to tightly attach the container 20 to theplate 10 by screwing through the first side container fixing hole 22 ofthe container 20 and into the plate fixing hole 32 of the plate.

FIG. 4B is a cross-sectional view of an exemplary fixing hole along lineB-B′ of FIG. 3. Referring to FIG. 4B, the container 20 is looselyattached to the plate 10 through a container fixing hole 24 on thesecond side of the container 20. For this purpose, a plate fixing hole34 is formed on the plate 10 to correspond to the container fixing hole24 on the second side of the container 20. In an embodiment, screwthreads are formed in the plate fixing hole 34 of the plate 10corresponding to the container fixing hole 24, but not in the containerfixing hole 24.

As shown in FIGS. 4A and 4B, buffers 52 and 54 can be interposed betweenthe container 20 and the plate 10 to prevent direct contact between thecontainer 20 and the plate 10 when they are attached by the screws 26and 42.

In an embodiment, the diameter of the container fixing hole 24 on thesecond side of the container 20 is larger than the container fixing hole22 on the first side of the container 20. Accordingly, the screw 42 usedin the second side container fixing hole 24 is shaped differently fromthe screw used in the first side container fixing hole 22. For example,the screw 42 includes a column portion 42 b inserted through the secondside container fixing hole 24 and a head portion 42 a integrally formedwith the column portion 42 b and having a diameter that is at leastlarger than the diameter of the second side container fixing hole 24.Thus, the screw 42 can cover the surrounding area of the second sidecontainer fixing hole 24 of the container 20. The column portion 42 bmay have a diameter narrower by a specified gap than the diameter of thesecond side container fixing hole 24. For instance, if the diameter ofthe column portion 42 b is “d,” and the second side fixing hole has adiameter “D,” the diameter “d” of the column 42 b may lie within a rangeof 0.3 D-0.7 D.

Accordingly, the screw 42 is not tightly attached on the second sidecontainer fixing hole 24 but passes through it, and fastens into thethreads formed in the plate fixing holes 32 and 34 corresponding to thecontainer fixing hole 24. Thus, the screw 42 is not fixed to the secondside container fixing hole 24, but is attached to the plate fixing hole34.

According to an embodiment of the present invention, the first side ofthe container 20 is attached to the plate 10 by fastening the screw 26into the threaded container fixing hole 22 and the correspondingthreaded plate fixing hole 32. Thus, the first side container fixinghole 22 of the container 20 is tightly attached by the screw 26 to theplate 10 through the container fixing hole 26 and the plate fixing hole32. On the other hand, the diameter of the container fixing hole 24 islarger than the diameter of the container fixing hole 22. Moreover, thecontainer fixing hole 24 is not threaded while the corresponding platefixing hole 34 is threaded for a screw. Thus, the screw 42 passesthrough the container fixing hole 24 on the second side of the container20 and is only screwed to the plate fixing hole 34. Accordingly, thecontainer 20 is attached more tightly through the container fixing hole22 than through the container fixing hole 24. Alternatively, thecontainer 20 is attached less tightly through the container fixing hole24 than through the container fixing hole 22. Thus, when the container20 expands due to heat, the space provided around the column portion 42b of the screw 42 allows the container 20 to expand around the secondside fixing screw 24 without being damaged. Thus, the container 20 isnot damaged by heat-induced expansion because one of the containerfixing holes 22 and 24 is not tightly attached to the plate 10.

As described above, damage to the container can be prevented by changingits connecting structure. For example, the connecting structure of thecontainer 20 is changed, so that one of the container fixing holes 22 ad24 is loosely attached to the plate 10. That is, the container 20 ismore tightly attached through container fixing hole 22 than throughcontainer fixing hole 24. Thus, the container fixing hole 22 and thecorresponding plate fixing hole 32 are threaded so that a screw 26 istightly fastened through both of the container fixing hole 22 and thecorresponding plate fixing hole 32. However, the container fixing hole24 on the second side has a diameter larger than that of the containerfixing hole 22 on the first side, and no threading is provided on thecontainer fixing hole 24, while only the plate fixing hole 34 isthreaded. Accordingly, a screw 42 slides through the container fixinghole 24 and is only screwed into the plate fixing hole 34, allowing thecontainer 20 to move relatively freely around the screw 42. Thus, whenthe container 20 expands due to heat, the space provided around thecolumn portion 42 b of the screw 42 allows the container 20 to expandaround the second side fixing screw 24 without being damaged. Thus, thecontainer 20 is not damaged by heat-induced expansion because one of thecontainer fixing holes 22 and 24 is less tightly attached to the plate10.

In another embodiment, the container can be made of a different materialto prevent damage to the container. By manufacturing the container witha material that is damage-resistant and highly heat-conductive, damageto the container can be prevented. Alternatively, damage to thecontainer can be prevented by changing both its connecting structure andthe material it is made of.

For example, titanium is a material with high strength and heatconductivity. By illuminating the metal titanium through a surfacetreatment (ABB), target material that does not cover a substrate can beprevented from being deposited on the container during thin filmmanufacturing. Other metals besides titanium may be used.

Due to titanium's high heat conductivity, when a container is made oftitanium, a lower heating temperature can be used in comparison topyrex. For example, a pyrex container requires a heating temperature ofabout 220° C. to maintain a substrate temperature of 120° C. Incontrast, maintaining the same substrate temperature can be obtained byheating a titanium container to about 180° C. Thus, energy is saved byusing a titanium container.

Moreover, due to the high strength of titanium, a container made oftitanium will not be damaged during transport or by high temperatureplasma. Moreover, titanium is known to have a higher heat expansion thanpyrex.

In an embodiment of the present invention, a liquid crystal panel isconstructed, by subjecting the substrate various repeating treatmentprocesses, such as thin film processing and etching. The sputteringapparatus described above in the various embodiments can be used forsuch thin film processing.

In an embodiment, a liquid crystal display (LCD) device is formed byattaching a thin film transistor (TFT) array substrate and a colorfilter (CF) substrate together to face each other with a specified cellgap therebetween, and filling the cell gap with a liquid crystalmaterial. A plurality of gate lines are arranged at regular intervalsalong a horizontal direction and a plurality of data lines are arrangedat regular intervals along a vertical direction on the TFT arraysubstrate to cross each other. Crossings of the data lines with the gatelines define pixel regions. Each pixel region includes a switchingdevice and a pixel electrode. In addition, red, green and blue colorfilters corresponding to the pixel regions are formed on the CFsubstrate. A black matrix is formed in a mesh shape that encompasses anouter edge of the color filters. The black matrix prevents colorinterference of light passing through the pixel regions. Furthermore, acommon electrode is formed on the CF substrate. The common electrode andthe pixel electrode generate an electric field through the liquidcrystal material. The array substrate and the color filter substrate caneach be processed through the sputtering device described in anyone ofthe above described embodiments, or equivalents thereof.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the sputtering apparatus ofthe present invention without departing from the spirit or scope of theinvention. Thus, it is intended that the present invention cover themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

1. A method of sputtering to prevent damage to a sputtering apparatus,comprising: attaching a container to a plate through a first containerfixing hole provided at a front side of the container by screwing afirst screw without forming a gap between a head portion of the firstscrew and a first buffer; and screwing the container only to the plateby sliding a second screw through a second container fixing holeprovided at the front side of the container positioned opposite to thefirst container fixing hole, wherein the second container fixing hole islarger than the first container fixing hole, wherein including insertinga column portion of the second screw through the second container fixinghole and forming a head portion of the second screw integrally with thecolumn portion, the head portion having a diameter larger than thediameter of the second container fixing hole, and wherein the columnportion of the second screw has a diameter narrower than the diameter ofthe second container fixing hole thereby forming a gap between the headportion of the second screw and a second buffer, wherein both sides ofthe container is disposed on the plate, wherein the second containerfixing hole is configured to prevent damage when the sputteringapparatus expands by heat, wherein a substrate is on the container, andwherein the first and second buffers are interposed between thecontainer and the plate.
 2. The method of claim 1, further comprisingthreading the first container fixing hole, and while leaving unthreadedthe second container fixing hole.
 3. The method of claim 2, wherein theattaching the container to the plate including screwing the containerboth through the first container fixing hole and into the plate.
 4. Themethod of claim 1, wherein the diameter of the column portion is afraction of the diameter of the second container fixing hole, and thefraction is in a range of about 0.3 to 0.7.